Detailed answer

Certain vitamin C serums can make the skin look dull due to several factors. Firstly, the formulation of the serum may not be suitable for your skin type or may contain ingredients that can cause inflammation or irritation. Secondly, some vitamin C serums may oxidize quickly when exposed to air, heat, or light, which can degrade their effectiveness and potentially lead to dull-looking skin. Additionally, using certain skincare products alongside vitamin C serums, such as those containing acidic ingredients or retinol, can lead to a chemical reaction that alters the pH balance of the skin, resulting in a dull appearance. Lastly, overuse or incorrect application of vitamin C serums can also contribute to dull-looking skin. It is advisable to choose a well-formulated serum that suits your skin type, store it properly, and avoid using conflicting products to maintain a bright and vibrant complexion.